1. Briefing
This deed contemplates improvements in a system for a direct and continuous monitoring of quick evolution defects in capacitive insulation that also allows monitoring in real time condensive bushings and other high voltage equipments. It also allows monitoring Bushing Potential Devices (BPDs) equipped bushings as well as monitoring bushing used in high voltage direct current (HVDC) systems.
2. Introduction
In high voltage equipments, such as power transformers and reactors, current transformers, potential transformers and others' bushings, the use of capacitive insulating systems, where the high voltage insulation in relation to ground potential is gradually done, with capacitive voltage dividers and using capacitive insulations systems, is most usual.
Due to the importance of such high voltage equipments for the reliability of the electric power generation, transmission and distribution, the monitoring in real time of their state is a more and more regular practice that aims at occasional defects precociously detecting and diagnosing therefore avoiding interruptions in power supply or “black-outs”.
Amongst the several parts of the equipments monitored for defects detection, capacitive type insulating systems, used in bushings, transformers, potential transformers and others, are pointed out once such insulating systems are submitted to high stresses and their total failure frequently provokes explosions as well as fires that may damage also other equipments in the nearness and cause heavy injuries to people around.